There are various differences in material requirements between low temperature resistant coatings and high temperature resistant coatings. The following is a detailed introduction for you:
In terms of chemical structure stability
Requirements for low-temperature resistant coating materials:
The key is to maintain the flexibility of molecular structure in low-temperature environments, avoiding material brittleness and cracking caused by temperature reduction. Like organic silicon materials, their molecular chains are relatively flexible, and the silicon oxygen bonds can still maintain a certain level of activity at low temperatures, allowing the coating to withstand low temperatures without being damaged.
For some polymer materials, it is necessary to have a suitable glass transition temperature (Tg), which should be much lower than the actual low-temperature ambient temperature used to ensure that they remain in a high elastic state at low temperatures and maintain good physical properties.
Requirements for high-temperature resistant coating materials:
Firstly, it must have a highly stable chemical structure that can withstand reactions such as chemical bond breakage and oxidation that may occur at high temperatures. For example, in ceramic materials such as silicon carbide and silicon nitride, their chemical bond energy is very high, which can maintain structural stability in high temperature environments and is not easily decomposed, thus ensuring that the coating can continue to function.
High temperature resistant coating materials often require good thermal rearrangement ability, that is, the molecular structure can adapt to high temperature environments through certain rearrangement at high temperatures, reducing coating damage caused by thermal stress and other factors.
Matching of thermal expansion coefficient
Requirements for low-temperature resistant coating materials:
It is generally hoped that the thermal expansion coefficient of the material is relatively close to the variation of the coated substrate in the low-temperature range, so that during the temperature reduction process, there will be no significant internal stress between the coating and the substrate due to the large difference in shrinkage degree, avoiding coating peeling, cracking and other situations. However, due to the slightly smaller overall amplitude of thermal expansion coefficient changes in low-temperature environments compared to high-temperature environments, the requirements in this regard are relatively less stringent.
Requirements for high-temperature resistant coating materials:
The matching of thermal expansion coefficient is extremely crucial because in high temperature environments, the thermal expansion coefficient of materials will undergo significant changes. If the thermal expansion coefficient of the coating does not match that of the substrate, during the heating and cooling cycles, the coating is easily prone to failure phenomena such as peeling, cracking, and delamination due to repeated thermal expansion and contraction stresses. When coating ceramic coatings on the surface of high-temperature metal components, it is necessary to modify the ceramic material to make its thermal expansion coefficient as compatible as possible with the metal substrate.
In terms of maintaining physical performance
Requirements for low-temperature resistant coating materials:
The main focus is on whether the material can maintain good flexibility, adhesion, and certain barrier properties at low temperatures. For example, polyurethane coating should still be able to tightly adhere to the substrate at low temperatures, and can block the corrosion of the substrate by external water vapor, corrosive media, etc., ensuring the normal use of the substrate in low-temperature environments.
The requirements for the hardness and other physical properties of the coating are relatively flexible, as long as it can ensure that it will not become brittle and damaged due to hardness at low temperatures.
Requirements for high-temperature resistant coating materials:
Emphasis is placed on maintaining sufficient physical properties such as hardness, strength, and wear resistance at high temperatures. For example, the high-temperature resistant coating on the surface of aircraft engine blades should be able to maintain its structural integrity under harsh working conditions such as high temperature and high-speed airflow erosion, and have the ability to resist airflow erosion and particle impact, ensuring the normal operation of the blades.
At the same time, high-temperature resistant coatings also need to have good thermal insulation performance, which can effectively block heat transfer and reduce the impact of high temperature on the substrate. For example, some insulation coatings in high-temperature kilns need to reduce heat loss in high-temperature environments and improve energy utilization efficiency.
In terms of oxidation resistance and corrosion resistance
Requirements for low-temperature resistant coating materials:
Although a certain degree of corrosion resistance is also required to cope with possible water vapor, chemical media, etc., due to the relatively slow rate of many chemical reactions in low-temperature environments, the requirements for its antioxidant performance are usually not as high as those for high-temperature resistant coatings. For example, the coating on the surface of low-temperature refrigeration equipment is mainly used to prevent water vapor condensation, corrosion by ordinary acidic and alkaline substances, and is less threatened by high-temperature oxidation.
Requirements for high-temperature resistant coating materials:
Antioxidant performance is of paramount importance, as the activity of oxidizing substances such as oxygen increases in high-temperature environments, making the material highly susceptible to oxidation and leading to coating failure. Like metal high-temperature protective coatings, they need to have good antioxidant capacity. By adding antioxidant components or having an antioxidant structure (such as forming a dense oxidation protective film), they can resist high-temperature oxidation and extend the service life of the coating.
It also needs to have strong corrosion resistance to cope with various complex chemical environments that may occur at high temperatures, such as the corrosion of coatings by corrosive components such as sulfur and chlorine in high-temperature gases, ensuring that the coating can provide protection in harsh high-temperature and highly corrosive environments.

Room termperature curing polysilazane, pls check IOTA 9150, IOTA 9150K.    
High termperature curing polysilazane, pls check IOTA 9108, IOTA 9118.